Snapshot A 36-year-old woman presents with upper extremity weakness and double vision. She recalls a period of right arm numbness almost a year prior, but has self-resolved over a few weeks. On physical examination, forward neck flexion causes the patient to experience a radiating shock-like sensation down her spine and upper extremities. (Multiple sclerosis; Lhermitte sign) Introduction Brachial Plexus Illustrations Nerve root anatomys key difference between cervical and lumbar spine is pedicle/nerve root mismatch cervical spine C6 nerve root travels under C5 pedicle (mismatch) lumbar spine L5 nerve root travels under L5 pedicle (match) extra C8 nerve root (no C8 pedicle) allows transition horizontal (cervical) vs. vertical (lumbar) anatomy of nerve root because of vertical anatomy of lumbar nerve root a paracentral and foraminal disc will affect different nerve roots because of horizontal anatomy of cervical nerve root a central and foraminal disc will affect the same nerve root Inspection, Palpation, ROM Inspection alignment in sagittal and coronal plane (e.g., kyphotic cervical spine) prior surgical scars (e.g., prior ulnar nerve trasnposition or carpal tunnel surgery) skin defects (e.g., cafe au lait spots associated with neurofibromatosis) muscle atrophy (e.g., palsy will see decrease deltoid and biceps mass) Palpation palpate local tenderness on the spinal axis, aymmetic ROM document range of motion in flexion, extension, rotation, and bend may give absolute degrees or relative to anatomic landmark (e.g, chin rotates to right shoulder) normal range of motion of cervical spine flexion: 50 extension: 60 rotation: 80 lateral bend: 45 Motor Testing Grade key muscles groups from 0-5 using ASIA Grading System include at least one muscle from each nerve root group (C5 to T1) Primary Motion Primary Muscle Innervation Nerve Root Shoulder abduction Deltoid Axillary n. C5 Shoulder internal rotation Subscapularis Subscapular n. C5 Shoulder external rotation Infraspinatus Suprascapular n. C5 Elbow flexion (palm up) Biceps & brachialis Musculocutaneous n. C5 Elbow flexion (thumb up) Brachioradialis Radial n. C6 Wrist extension ECRL Radial n. C6 Wrist supination Supinator Deep branch Radial n. C6 Elbow extension Triceps Radial n. C7 Wrist flexion FCR & PL Median n. C7 Wrist pronation PT & PQ Median n. C7 MCP & PIP Finger flexion FDS Median n. C8 DIP Finger FDP Ulnar n. & AIN C8 Thumb extension EPL PIN C8 Finger abduction Interossei Deep branch Ulnar n. T1 Sensory Exam Grade senory in C5 to T1 dermatomes score using ASIA Sensory Grading System score major sensory types in all patients pain (prick with sharp object such as paper clip, broken cue tip) light touch (stroke lightly with finger) score minor sensory types for focused exam vibration (focused exam) temperture (focused exam) two-point descrimination (focused exam) Provacative Tests Spurlings Test foraminal compression test that is specific, but not sensitive, in diagnosing acute radiculopathy. it is performed by rotating head toward the affected side, extending the neck, and then applying and axial load (applying downward pressure on the head) the test is considered positive if pain radiates into the ipsilateral arm when the test is performed for 30 seconds. Hoffman's Test a positive test is sensitive but not specific for cervical myelopathy performed in one of two ways hold and secure the middle phalanx of the long finger and then flick the distal phalanx into an extended position. Involuntary contraction of the thumb IP joint is a positive test. hold and secure the distal phalanx of the long finger and then flick the distal phalanx into an extended position. Involuntary contraction of the thumb IP joint is a positive test. Lhermitte Sign a positive test is specific but not sensitive forcervical spinal cord compression and myelopathy test is positive cervical flexion or extension leads to shockline sensation radiating down spinal axis and into arms and/or legs Differential Diagnosis Provacative Tests Neer Impingement Test rule out shoulder impingement or other shoulder pathologies as cause of pain. Cubital Tunnel Tinnel Sign rule out Cubital Tunnel Syndrome as cause for paresthesia in ulnar hand Carpal Tunnel Compression Test (Durkan's test) rule out carpal tunnel syndrome as cause for pain/paresthesias in hand or decreased dexterity Gait Antalgic gait caused by gaurding for pain in affected extremity due to hip and knee pathology severe radicular symptoms Trendelenburg gait caused by painful arthritis of hip or gluteus medius weakness wide-based shuffling gait due to neurologic disorder including myelopathy steppage or lateral swing gait a method of gait compensation for a foot drop (weakness ankle dorsiflexion and toe extension)